1. Field of the Invention
The present invention relates to a discharging control method, related driving method and driving device, and more particularly, to a discharging control method capable of clearing blur without additional control signals, related driving method and driving device.
2. Description of the Prior Art
A liquid crystal display (LCD) is a flat panel display which has the advantages of low radiation, light weight and low power consumption and is widely used in various information technology (IT) products, such as notebook computers, personal digital assistants (PDA), and mobile phones. An active matrix thin film transistor (TFT) LCD is the most commonly used transistor type in LCD families, and particularly in the large-size LCD family. A driving system installed in the LCD includes a timing controller, source drivers and gate drivers. The source and gate drivers respectively control data lines and scan lines, which intersect to form a cell matrix. Each intersection is a cell including crystal display molecules and a TFT. In the driving system, the gate drivers are responsible for transmitting scan signals to gates of the TFTs to turn on the TFTs on the panel. The source drivers are responsible for converting digital image data, sent by the timing controller, into analog voltage signals and outputting the voltage signals to sources of the TFTs. When a TFT receives the voltage signals, a corresponding liquid crystal molecule has a terminal whose voltage changes to equalize the drain voltage of the TFT, which thereby changes its own twist angle. The rate that light penetrates the liquid crystal molecule is changed accordingly, allowing different colors to be displayed on the panel.
When the LCD is turned off, parts of the image displayed by the LCD may persist on the LCD if the drain voltages used for controlling the liquid crystal molecules is not immediately cleared. In order to clear the remain images (i.e. blur), the prior art may utilize additional control signals to reset the drain voltages used for controlling the liquid crystal molecules, which increases the number of signal lines and the hardware cost of the control circuit in the LCD. Thus, how to reset the drain voltage used for controlling the liquid molecules when the LCD is turned off becomes a topic to be discussed.